Modular Combat 2 will have its own custom maps and we will not be able to use maps made by anyone else (Alien Swarm maps use BSP version 21 while everything else uses BSP 20 or less).
If you've ever had an idea for a map but don't have the skills to actually make it, then share the idea with us! We might be able to turn your idea into a reality. Your design suggestions can fall into 2 categories: BoSS facility (themed maps) or everything else (unthemed maps). Be as detailed as possible, include any sketches you have made in MS Paint, etc. Try not to rip off idea's from movies or other games as we want to stay as unique as possible.
If you're wondering what the BoSS facility is, its the building in which all the combat simulations are taking place in and its run by the BoSS AI (when you're killed by a monster, it says BoSS killed you). I imagine the facility is like the facility in portal, except there also needs to be maps that take place in area's where combat normally wouldn't occur (like offices, employee lounge, storage rooms, parking lot, industrial/machine area, etc).
Keeping track of idea's here on ModDB will get complicated when there are multiple pages (not to mention the fact it will be harder for you to edit your comment if you forget which page its on). So i suggest you make your map design suggestion at our forum in this thread (you will need to register an account first).